Cimorene

I love my therapy putty. It's good for hand strength, sensory integration, and for clenching in your fist and digging your nails into when you're furious. Ordinary putty works for this, but therapy-grade putty is firmer and more satisfying to clench in fury.

You can bring something to chomp angrily on - the end of a pencil, if you don't mind splinters all over your desk; or there are silicon pencil toppers that are harder to destroy like that.

Some people do prayer beads, meditation beads, or the rosary.

"I knit so I do not kill people" is also an icon for a reason, but in your situation you might draw people making conversation about your knitting.

I like nature sounds better than instrumental music, for calming - rain in particular.

There's aromatherapy - personally, I find scents overwhelming if I can't get away from them, but a few drops of perfume oil on a hankie or tissue in a little plastic bag works: I can take it out and sniff it, then put it away and not smell it.

The iPhone Bejeweled app (maybe the Android version too? I don't know) has a Zen mode with nature sounds and timed lights to synch your breathing to. And it still has satisfying explosions.

Then there's the old 'put cartoon mp4s on your phone and keep taking five minute toilet breaks when you can to watch them with your earphones on in a toilet stall' trick. Can also be done with fanfic or books or puzzles.